/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

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#include <processor3d/shadow3dextractor.hxx>

#include <primitive3d/shadowprimitive3d.hxx>

#include <drawinglayer/primitive2d/shadowprimitive2d.hxx>

#include <drawinglayer/primitive2d/unifiedtransparenceprimitive2d.hxx>

#include <drawinglayer/primitive3d/transformprimitive3d.hxx>

#include <drawinglayer/primitive3d/polygonprimitive3d.hxx>

#include <basegfx/polygon/b2dpolygontools.hxx>

#include <drawinglayer/primitive3d/polypolygonprimitive3d.hxx>

#include <basegfx/polygon/b2dpolypolygontools.hxx>

#include <drawinglayer/primitive2d/PolygonHairlinePrimitive2D.hxx>

#include <drawinglayer/primitive2d/PolyPolygonColorPrimitive2D.hxx>

#include <drawinglayer/primitive3d/drawinglayer_primitivetypes3d.hxx>

#include <osl/diagnose.h>

#include <rtl/ref.hxx>

#include <utility>

using namespace com::sun::star;

namespace drawinglayer::processor3d

{

        // as tooling, the process() implementation takes over API handling and calls this

        // virtual render method when the primitive implementation is BasePrimitive3D-based.

        void Shadow3DExtractingProcessor::processBasePrimitive3D(const primitive3d::BasePrimitive3D& rCandidate)

        {

            // it is a BasePrimitive3D implementation, use getPrimitive3DID() call for switch

            switch(rCandidate.getPrimitive3DID())

            {

                case PRIMITIVE3D_ID_SHADOWPRIMITIVE3D :

                {

                    // shadow3d object. Call recursive with content and start conversion

                    const primitive3d::ShadowPrimitive3D& rPrimitive = static_cast< const primitive3d::ShadowPrimitive3D& >(rCandidate);

                    // set new target

                    primitive2d::Primitive2DContainer aNewSubList;

                    primitive2d::Primitive2DContainer* pLastTargetSequence = mpPrimitive2DSequence;

                    mpPrimitive2DSequence = &aNewSubList;

                    // activate convert

                    const bool bLastConvert(mbConvert);

                    mbConvert = true;

                    // set projection flag

                    const bool bLastUseProjection(mbUseProjection);

                    mbUseProjection = rPrimitive.getShadow3D();

                    // process content

                    process(rPrimitive.getChildren());

                    // restore values

                    mbUseProjection = bLastUseProjection;

                    mbConvert = bLastConvert;

                    mpPrimitive2DSequence = pLastTargetSequence;

                    // create 2d shadow primitive with result. This also fetches all entries

                    // from aNewSubList, so there is no need to delete them

                    rtl::Reference<primitive2d::BasePrimitive2D> pNew = new primitive2d::ShadowPrimitive2D(

                        rPrimitive.getShadowTransform(),

                        rPrimitive.getShadowColor(),

                        0,  // shadow3d doesn't have rPrimitive.getShadowBlur() yet.

                        std::move(aNewSubList));

                    if(rPrimitive.getShadowTransparence() > 0.0)

                    {

                        // create simpleTransparencePrimitive, add created primitives

                        primitive2d::Primitive2DContainer aNewTransPrimitiveVector { pNew };

                        pNew = new primitive2d::UnifiedTransparencePrimitive2D(

                            std::move(aNewTransPrimitiveVector),

                            rPrimitive.getShadowTransparence());

                    }

                    mpPrimitive2DSequence->push_back(pNew);

                    break;

                }

                case PRIMITIVE3D_ID_TRANSFORMPRIMITIVE3D :

                {

                    // transform group. Remember current transformations

                    const primitive3d::TransformPrimitive3D& rPrimitive = static_cast< const primitive3d::TransformPrimitive3D& >(rCandidate);

                    const geometry::ViewInformation3D aLastViewInformation3D(getViewInformation3D());

                    // create new transformation; add new object transform from right side

                    const geometry::ViewInformation3D aNewViewInformation3D(

                        aLastViewInformation3D.getObjectTransformation() * rPrimitive.getTransformation(),

                        aLastViewInformation3D.getOrientation(),

                        aLastViewInformation3D.getProjection(),

                        aLastViewInformation3D.getDeviceToView(),

                        aLastViewInformation3D.getViewTime(),

                        aLastViewInformation3D.getExtendedInformationSequence());

                    updateViewInformation(aNewViewInformation3D);

                    if(mbShadowProjectionIsValid)

                    {

                        // update buffered WorldToEye and EyeToView

                        maWorldToEye = getViewInformation3D().getOrientation() * getViewInformation3D().getObjectTransformation();

                        maEyeToView = getViewInformation3D().getDeviceToView() * getViewInformation3D().getProjection();

                    }

                    // let break down

                    process(rPrimitive.getChildren());

                    // restore transformations

                    updateViewInformation(aLastViewInformation3D);

                    if(mbShadowProjectionIsValid)

                    {

                        // update buffered WorldToEye and EyeToView

                        maWorldToEye = getViewInformation3D().getOrientation() * getViewInformation3D().getObjectTransformation();

                        maEyeToView = getViewInformation3D().getDeviceToView() * getViewInformation3D().getProjection();

                    }

                    break;

                }

                case PRIMITIVE3D_ID_POLYGONHAIRLINEPRIMITIVE3D :

                {

                    // PolygonHairlinePrimitive3D

                    if(mbConvert)

                    {

                        const primitive3d::PolygonHairlinePrimitive3D& rPrimitive = static_cast< const primitive3d::PolygonHairlinePrimitive3D& >(rCandidate);

                        basegfx::B2DPolygon a2DHairline;

                        if(mbUseProjection)

                        {

                            if(mbShadowProjectionIsValid)

                            {

                                a2DHairline = impDoShadowProjection(rPrimitive.getB3DPolygon());

                            }

                        }

                        else

                        {

                            a2DHairline = basegfx::utils::createB2DPolygonFromB3DPolygon(rPrimitive.getB3DPolygon(), getViewInformation3D().getObjectToView());

                        }

                        if(a2DHairline.count())

                        {

                            a2DHairline.transform(getObjectTransformation());

                            mpPrimitive2DSequence->push_back(

                                new primitive2d::PolygonHairlinePrimitive2D(

                                    std::move(a2DHairline),

                                    basegfx::BColor()));

                        }

                    }

                    break;

                }

                case PRIMITIVE3D_ID_POLYPOLYGONMATERIALPRIMITIVE3D :

                {

                    // PolyPolygonMaterialPrimitive3D

                    if(mbConvert)

                    {

                        const primitive3d::PolyPolygonMaterialPrimitive3D& rPrimitive = static_cast< const primitive3d::PolyPolygonMaterialPrimitive3D& >(rCandidate);

                        basegfx::B2DPolyPolygon a2DFill;

                        if(mbUseProjection)

                        {

                            if(mbShadowProjectionIsValid)

                            {

                                a2DFill = impDoShadowProjection(rPrimitive.getB3DPolyPolygon());

                            }

                        }

                        else

                        {

                            a2DFill = basegfx::utils::createB2DPolyPolygonFromB3DPolyPolygon(rPrimitive.getB3DPolyPolygon(), getViewInformation3D().getObjectToView());

                        }

                        if(a2DFill.count())

                        {

                            a2DFill.transform(getObjectTransformation());

                            mpPrimitive2DSequence->push_back(

                                new primitive2d::PolyPolygonColorPrimitive2D(

                                    std::move(a2DFill),

                                    basegfx::BColor()));

                        }

                    }

                    break;

                }

                default :

                {

                    // process recursively

                    process(rCandidate.get3DDecomposition(getViewInformation3D()));

                    break;

                }

            }

        }

        Shadow3DExtractingProcessor::Shadow3DExtractingProcessor(

            const geometry::ViewInformation3D& rViewInformation,

            basegfx::B2DHomMatrix aObjectTransformation,

            const basegfx::B3DVector& rLightNormal,

            double fShadowSlant,

            const basegfx::B3DRange& rContained3DRange)

        :   BaseProcessor3D(rViewInformation),

            mpPrimitive2DSequence(&maPrimitive2DSequence),

            maObjectTransformation(std::move(aObjectTransformation)),

            maLightNormal(rLightNormal),

            mfLightPlaneScalar(0.0),

            mbShadowProjectionIsValid(false),

            mbConvert(false),

            mbUseProjection(false)

        {

            // normalize light normal, get and normalize shadow plane normal and calculate scalar from it

            maLightNormal.normalize();

            maShadowPlaneNormal = basegfx::B3DVector(0.0, sin(fShadowSlant), cos(fShadowSlant));

            maShadowPlaneNormal.normalize();

            mfLightPlaneScalar = maLightNormal.scalar(maShadowPlaneNormal);

            // use only when scalar is > 0.0, so the light is in front of the object

            if(mfLightPlaneScalar <= 0.0 || basegfx::fTools::equalZero(mfLightPlaneScalar))

                return;

            // prepare buffered WorldToEye and EyeToView

            maWorldToEye = getViewInformation3D().getOrientation() * getViewInformation3D().getObjectTransformation();

            maEyeToView = getViewInformation3D().getDeviceToView() * getViewInformation3D().getProjection();

            // calculate range to get front edge around which to rotate the shadow's projection

            basegfx::B3DRange aContained3DRange(rContained3DRange);

            aContained3DRange.transform(getWorldToEye());

            maPlanePoint.setX(maShadowPlaneNormal.getX() < 0.0 ? aContained3DRange.getMinX() : aContained3DRange.getMaxX());

            maPlanePoint.setY(maShadowPlaneNormal.getY() > 0.0 ? aContained3DRange.getMinY() : aContained3DRange.getMaxY());

            maPlanePoint.setZ(aContained3DRange.getMinZ() - (aContained3DRange.getDepth() / 8.0));

            // set flag that shadow projection is prepared and allowed

            mbShadowProjectionIsValid = true;

        }

        Shadow3DExtractingProcessor::~Shadow3DExtractingProcessor()

        {

            OSL_ENSURE(maPrimitive2DSequence.empty(),

                "OOps, someone used Shadow3DExtractingProcessor, but did not fetch the results (!)");

        }

        basegfx::B2DPolygon Shadow3DExtractingProcessor::impDoShadowProjection(const basegfx::B3DPolygon& rSource)

        {

            basegfx::B2DPolygon aRetval;

            for(sal_uInt32 a(0); a < rSource.count(); a++)

            {

                // get point, transform to eye coordinate system

                basegfx::B3DPoint aCandidate(rSource.getB3DPoint(a));

                aCandidate *= getWorldToEye();

                // we are in eye coordinates

                // ray is (aCandidate + fCut * maLightNormal)

                // plane is (maPlanePoint, maShadowPlaneNormal)

                // maLightNormal.scalar(maShadowPlaneNormal) is already in mfLightPlaneScalar and > 0.0

                // get cut point of ray with shadow plane

                const double fCut(basegfx::B3DVector(maPlanePoint - aCandidate).scalar(maShadowPlaneNormal) / mfLightPlaneScalar);

                aCandidate += maLightNormal * fCut;

                // transform to view, use 2d coordinates

                aCandidate *= maEyeToView;

                aRetval.append(basegfx::B2DPoint(aCandidate.getX(), aCandidate.getY()));

            }

            // copy closed flag

            aRetval.setClosed(rSource.isClosed());

            return aRetval;

        }

        basegfx::B2DPolyPolygon Shadow3DExtractingProcessor::impDoShadowProjection(const basegfx::B3DPolyPolygon& rSource)

        {

            basegfx::B2DPolyPolygon aRetval;

            for(sal_uInt32 a(0); a < rSource.count(); a++)

            {

                aRetval.append(impDoShadowProjection(rSource.getB3DPolygon(a)));

            }

            return aRetval;

        }

        const primitive2d::Primitive2DContainer& Shadow3DExtractingProcessor::getPrimitive2DSequence() const

        {

            return maPrimitive2DSequence;

        }

} // end of namespace

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